The immune system in an organism functions to protect against infection by identifying and killing foreign pathogens. It is made up of special cells, proteins, tissues, and organs. It detects pathogens ranging from viruses to parasitic worms and distinguishes them from the organism's normal cells and tissues. But sometimes the immune system fails to function properly and this can lead to illness. For example, deregulation of the inflammatory response, such as sustained activation of macrophages, can occur, provoking inflammatory diseases. Inflammation plays crucial roles in the pathogenesis of various chronic diseases, including atherosclerosis, metabolic disorders such as diabetes, autoimmune diseases, cancer, rheumatoid arthritis, inflammatory bowel disease, systemic lupus erythematosus, and multiple sclerosis. Theses chronic inflammatory diseases affect almost half a billion of people worldwide and they represent major health problems and economic burden on our society. Moreover, many of these diseases are debilitating and are becoming increasingly common in our aging society.
Chronic low-grade inflammation, which is primarily mediated by innate and adaptive immune cells, has emerged as a key excessive or sustained link between obesity and metabolic disorders including dyslipidemia and diabetes. Moreover, it is widely accepted that atherosclerosis is a chronic inflammatory disorder. Chronic inflammatory processes in arteries lead to atherosclerotic plaque formation resulting in tissue ischemia, including acute myocardial infarction and stroke. Autoimmune diseases including rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) are characterized by the body's immune responses being directed against its own tissues, causing prolonged inflammation and subsequent tissue destruction. And also, it is well known that inflammation is crucial for cancer development, progression and metastasis. In these inflammatory situations where the immune systems is not engaged in protecting the host from infection or injury and promoting tissue repair, macrophages activation critically participates in such uncontrolled sustained inflammation which contributes to various diseases. Thus, new methods to control pathological activation of macrophages are useful.